(19)
(11) EP 1 132 146 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
01.06.2005 Bulletin 2005/22

(43) Date of publication A2:
12.09.2001 Bulletin 2001/37

(21) Application number: 01104105.0

(22) Date of filing: 21.02.2001
(51) International Patent Classification (IPC)7: B05C 11/10, H01L 21/56, B05C 17/005
(84) Designated Contracting States:
AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR
Designated Extension States:
AL LT LV MK RO SI

(30) Priority: 06.03.2000 US 519298

(71) Applicant: NORDSON CORPORATION
Westlake, Ohio 44145-1119 (US)

(72) Inventors:
  • Bouras, Carlos E.
    Encinitas, California 92024 (US)
  • Mellos, Nick I.
    San Diego, California 92110 (US)

(74) Representative: Eisenführ, Speiser & Partner 
Patentanwälte Rechtsanwälte Postfach 10 60 78
28060 Bremen
28060 Bremen (DE)

   


(54) Anti-float plunger for pneumatically actuated syringe


(57) An anti-float plunger (10) for a pneumatically actuated syringe includes an inner cylindrical (12) ring with two open ends held within a cylindrical cover (14) having one open end and one closed end. The open end is at the backside of the plunger. The closed end is at the frontside, in contact with liquid to be forced through the syringe outlet. The cover (14) includes an outer flexible wiper (18) extending around the circumference. This wiper maintains an airtight seal with the syringe walls even when the walls bulge outwardly due to excessive backside pressure. The cover also includes a deformable membrane (16) at the closed end, which deforms away from the outlet to alleviate residual pressure buildup on the liquid in the frontside. This structure eliminates air entrapment within the syringe, while also preventing residual pressure buildup within the syringe.






Search report